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 A054399 Decimal expansion of the constant Product_{i=1..inf} ((1-3/(2*(i+1)))^(1/2^i). 2

%I

%S 3,8,1,6,8,8,3,3,8,3,3,9,6,8,5,3,0,1,3,0,1,4,1,7,9,9,7,9,7,7,7,4,5,0,

%T 3,6,4,4,3,5,8,9,8,0,2,7,4,1,8,7,6,7,5,5,3,9,5,2,9,0,6,0,4,7,6,8,9,9,

%U 4,7,6,6,0,8,8,8,1,9,7,5,8,6,9,7,5,7,0,3,7,6,1,6,4,4,2,2,8,0,6,7,9,9,7,7,1

%N Decimal expansion of the constant Product_{i=1..inf} ((1-3/(2*(i+1)))^(1/2^i).

%D D.-Z. Du and F. K. Hwang, Combinatorial Group Testing and Its Applications, World Scientific, 2nd ed., 2000; p. 37.

%e .381688338339685...

%t Exp[2*Derivative[1, 0][PolyLog][0, 1/2] - Derivative[0, 1, 0][LerchPhi][1/2, 0, 1/2]/2] // RealDigits[#, 10, 105]& // First (* _Jean-François Alcover_, Feb 19 2013 *)

%o (PARI)\p 500; prodinf(n=1,((1-3/(2*(n+1)))^(1/2^n)))

%Y A054400/4.

%K nonn,easy,cons

%O 0,1

%A _N. J. A. Sloane_, May 22 2000

%E More terms from _Jason Earls_, Jun 28 2001

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Last modified August 12 23:19 EDT 2020. Contains 336440 sequences. (Running on oeis4.)